In an RPG, the opposite of an OptionalPartyMember. That is, someone who you ''have'' to have in your group, usually due to plot reasons. Depending on the story, they may leave after their work is done, [[SoLongAndThanksForAllTheGear taking with them everything they had]], or they may stick around with your RagtagBunchOfMisfits.

A slightly less annoying version is requiring certain party members to raise specific {{Event Flag}}s. You don't ''have'' to put Bob into the party so he can unlock the door to the underground base... unless you want HundredPercentCompletion.

This can also be ButThouMust, if the game ''appears'' to give you a choice, but then forces you to use the characters it wants you to anyway. If it's the main protagonist that's forced to be in your party at all times (which is almost always the case anyways), that's CantDropTheHero.
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!!Examples:

[[foldercontrol]]

[[folder: Adventure Game ]]

* In ''ManiacMansion'', TheHero Dave is required to participate in the rescue, while you can choose two other characters to use at the start of the game.

[[/folder]]

[[folder: Roguelike ]]

* This happens frequently in the ''VideoGame/PokemonMysteryDungeon'' series, particularly in the games after the first. You're often denied the ability to bring any party members of your own choosing in the story dungeons, either having to manage with just you and your partner or being forced to take along a NPC, as well (Who annoyingly, need to survive through the dungeon and ''cannot be issued commands'' like normal party members, which can lead to losses via ArtificialStupidity).
** Gates To Infinity is more merciful about this, as the Pokemon who you're forced to take are either an official part of your team (Meaning you can level them up and customize them to your liking beforehand) or are extremely overpowered, plus it no longer matters if they get KO'd and you can issue them orders.

[[/folder]]

[[folder: Real Time Strategy ]]

* ''DawnOfWar II'' has CantDropTheHero in full effect. The first expansion ''Chaos Rising,'' plays with this trope. While the Force Commander is still mandatory, certain squads will gain corruption if forced to stay behind for certain missions (though you are notified of this before you launch). The second expansion, ''Retribution'' does away with this.

[[/folder]]

[[folder: Role Playing Game ]]

* Various characters during the seven heroes' games in ''VideoGame/SagaFrontier'' ''have'' to join your party just to advance the plot. Others, like [[TheAlcoholic Gen]] and Fuse are required to do certain quests.
* A few of the stars in ''{{Suikoden}}'' games get thrown into your party for plot. Luckily, due to the game's levelling system, even if they're weak when you get them, they catch up fairly quickly. These are also the characters that tend to get the most characterization.
** The [[SuikodenI first game]] was probably the worst about this, to the point where half of your six-person party was predetermined for the last stretch of the plot, right up to the final boss. By contrast, ''SuikodenV'' included four 'extra' party slots (for a total of ten) where you could put non-combatants and spare members. So if somebody was forced into your party for plot reasons and you didn't care to use them/they were ''way'' too underleveled, you could just stick them in there and drag them along without worrying about dead weight.
* Your party is perpetually altering itself in ''VideoGame/FinalFantasyIV'', but it's always doing so at the story's discretion.
* ''VideoGame/FinalFantasyVI'' is an odd case in that this happens frequently in the first half of the game (such as with Banon's EscortMission, or Locke and Celes being mandatory for the opera house storyline), but in the second half, almost nobody is ''technically'' required except for a few characters. You could go straight to the final dungeon with only three characters if you wanted to.
** A more minor example of the Event Flag version of this trope occurs in cutscenes after you can begin swapping party members in and out of your group. While dialogue is largely the same regardless of who is with you, particular characters will get lines attributed to them specifically. If that character is not in your group the line will simply have quotation marks around it and no named speaker
* ''VideoGame/FinalFantasyVII'' '''loves''' this trope; at various points in the game, one character or another is required to be in your party to advance the plot, whether you like it or not.
** Barret forces himself into the party as they investigate who is framing him.
** Red XIII is forced onto you when you explore the caves in Cosmo Canyon as he learns about his father.
** Aerith is forced into your party as you explore the Temple of the Ancients so she can understand herself and her ancestors. [[spoiler:Meta-explanation: it's required because she's about to leave the party. And no, [[KilledOffForReal you are not]] [[TearJerker getting her back]]. Can also be a PlayerPunch if you were trying to get her together with Cloud.]]
** Done once again in the Whirlwind Maze where Tifa forces herself into your active party so she can see Sephiroth defeated once and for all. However, [[spoiler: the game forces Tifa to join you so that she can see that Cloud's memories of the Nibelheim incident are fragmented and made up, forcing her to spill the beans about what really happened.]] What makes this example particularly frustrating is that she gets shoehorned into the party ''right before a boss fight'', quickly turning her into TheLoad if you haven't been training her.
** When Shinra attempts to use the rocket in Rocket Town, Cid forces himself into your party so he can personally kick Shinra's ass.
*** [[spoiler:Cid also becomes the lead character for a little while when Cloud is forced out of the group. Hope you've given him some decent levels and gear...]]
* In ''VideoGame/FinalFantasyVIII'', during the last portion of Disc 1, you are forced to use the split up teams of Squall, Irvine, and (later on) Rinoa as well as Quistis, Zell, and Selphie. On Disc 2, when visiting the now under siege Balamb, Squall ''must'' have Zell in the party.
* ''VideoGame/FinalFantasyIX'' does this constantly until Disc 3. It also does the inverse, having characters just randomly walk away so that you can't add them to the party.
* In ''VideoGame/FinalFantasyX'', while you can usually switch characters at any time, there are a few parts where you have to fight underwater - and that means only Tidus, Wakka and Rikku can be in your party for those parts, since they're the only ones who know how to fight in the water.
** You can recruit/remove Wakka from the Besaid Aurochs team, but never Tidus (you don't have to play him, but he takes up a slot).
* ''VideoGame/FinalFantasyXIII'' is an absurd case. You can't switch party ''at all'' until you reach the Ark. Read: Chapter 11, around 18+ hour of gameplay. Even when the group's shown to be together, you can't just switch anybody out until then. The game plays the example a bit straighter at the conclusion of Chapter 10, though, as you can have anyone in the party, as long as Lightning is the leader.
* Happens quite a bit in ''SonicChronicles'', whenever you must split into teams. Usually, some choices are already pre-selected for you, which can be a pain as it locks out certain combination attacks.
** One especially annoying example is Omega, who is LostForever if you don't find him in Eggman's City. Better hope you remembered to bring Shadow or Rouge along if you don't want him to try and ''murder Eggman''.
* The ''[[DotHackGUGames .hack]]'' games would occasionally require you to use specific teams for story events. When this happened, you could bet you were going to see an FMV before the dungeon was out. There were also side-dungeons which your party members invited you to, thus requiring you to use that particular person. At one point this results in an inadvertent TwoTimerDate when Kite is invited to the same dungeon by both Black Rose and Terajima Ryoko.
** The sequel pretty much forces at least one member for nearly every story dungeon. Likewise you're team for the Arena story battles are always Haseo/Atoli/Silabus for Vol 1, Haseo/Atoli/Alkaid (Haseo/Kuhn/Endrance for the finale) in Vol 2 and Haseo/Atoli/Kuhn for Vol 3. And whenever AIDA is confirmed in a dungeon you can only take someone who has an Avatar there.
* In ''PlanescapeTorment'', Annah is necessary to progress into the Lower Ward
** Not actually true. You can find Annah in the area immediately outside of the mortuary at the start of the game and it's possible to start a fight with her and kill her. The game then works around her required presence.
* In ''VideoGame/TalesOfSymphonia'', Collette is required in all of the boss fights at the end of Sylvarant's temples, while Sheena is required for all summon seals. Also, in order to get the location information for monsters into your Monster Book, you need to use the Magic Lens with Raine, not any of the other characters. Raine is also required for the Windmaster boss fight, because she is participating in the ritual, and Lloyd is required for [[spoiler:the third battle with Yggdrasill, the [[DuelBoss third battle with Kratos]] and the battle with Origin]].
* [[Disney/{{Mulan}} Mulan]] (as Ping), [[VideoGame/FinalFantasyX Auron]], [[Franchise/PiratesOfTheCaribbean Jack Sparrow]], and [[Disney/TheLionKing Simba]] at certain story points in ''VideoGame/KingdomHeartsII''. Only the third of these has an "[[TheUndead exc]][[HeroMustSurvive use]]" for his requirement.
** Also in the same game, during the last boss battle in [[Film/{{Tron}} Space Paranoids]], the party requires [[BadassBookworm Tron]] to be active during the battle with the MCP[[note]]since he can only be damaged with the "Delete" reaction command[[/note]], even though he didn't get the (!) that the previously mentioned got when they were required. Fortunately, since party members can be switched mid-combat, it's not much of an issue.
** [[spoiler: During the final battle against Xemnas, Riku will be Sora's only remaining party member after the first stage. Like with Jack Sparrow before, [[HeroMustSurvive it's game over if Riku's HP hits zero]]]].
** In the [[VideoGame/KingdomHearts first game]], [[Disney/PeterPan Peter Pan]] is required to be active to fight the [[BonusBoss Phantom]] in Neverland.
* The Hierophant/Lovers full moon in ''{{Persona 3}}'' requires you to bring Yukari (because your party was fixed last time and did not include her) so you can fall into The Lovers's mind control. This is slightly more lenient in ''Portable'' for the heroine -- you'll need a full party, which ensures that you'll have to bring at least one of the guys.
** In "The Answer", [[spoiler:your party will consist solely of Aigis and Metis for the 2-on-2 party battles before the final door.]]
* ''VideoGame/KnightsOfTheOldRepublic'' gives you numerous quests that cannot be completed without a certain party member. You get forced to take Carth when you first enter Taris, you have to have Mission to get into the Vulkar base, T3-M4 is required to get into the Sith base, you need HK-47 to complete the light-side track with the Sand People on Tantooine, you need Bastilla for the beginning of Dantooine, etc.
** And railroads you entirely on the Leviathan level, by locking you with Carth and Bastila. Of course, because of [[HeroicSacrifice certain]] [[RoaringRampageOfRevenge story]] [[TheReveal events]], the whole thing wouldn't work without them. The ''Brotherhood of Shadow'' mod also forces this in several places. Justified on some of it, as you're [[spoiler: playing a flashback to some event in your life as Revan]]..
*** On the unknown planet, your party members will leave when you prepare to open up the temple, but Jolee and Juhani will come back and insist on accompanying you in.
** In [[VideoGame/KnightsOfTheOldRepublicIITheSithLords the sequel]], you need Bao-Dur to track down the Ebon Hawk on Telos. Mandalore is needed for the Iziz level before the Onderon Civil War. Kreia is required in your party during the civil war at Onderon. Also, during the assault on the ''Ravager'', you are forced to bring Visas and Mandalore with you.
* This is continued in ''VideoGame/StarWarsTheOldRepublic'', where most classes has certain missions that need a certain companion. In addition, any mission classified as a Companion Mission will require that companion to accompany you.
** The Sith Inquisitor is specifically instructed to take [[spoiler:Khem Val with him for Zash's ritual, because Zash accidentally possessing him is a major plot point through the rest of the Inquisitor storyline]].
** The Republic Trooper has one mission where you have to use certain companions for certain segments of the mission, and switch out when moving on to the next one. [[JustifiedTrope Justified]] because it's a sabotage assault on a superweapon, and you need your demolitions expert to plant the bombs, your tech guy to shut down enemy systems, etc.
** The Jedi Knight takes [[spoiler:Kira along on the mission where you learn she's actually a [[TykeBomb Child of the Emperor]]]].
* In ''VideoGame/ChronoTrigger'', every character (except [[spoiler:Magus]]) is forced on you for a dungeon when he or she first joins. Frog and Ayla get ''two'' such dungeons and Robo is a mandatory party member when you're exploring the factory ruins. {{C|antDropTheHero}}rono is forced on you for most of the game, but eventually, he becomes optional.
** Also, there are optional dungeons later in the game that require certain characters to be in your party, namely Robo and Marle. Frog, Robo, and Lucca are each required to be in your party to finish certain optional quests, but they're not required for the dungeons/fights that are part of those quests. Finally, Magus gets some special dialogue in two others but is not required for them.
* ''VideoGame/ChronoCross'' has this with Serge ([[spoiler:and later, Lynx, after Serge's body is swapped with Lynx's]]). He must be in the party for the entire game, and there's no way to remove him. Playing on a NewGamePlus, though, will earn you an item that allows you to switch Serge out for someone else in battle.
* A handful of battles in ''VideoGame/TheLegendOfDragoon'' require certain party members to fight with you at certain points. Lavitz must be in your party [[spoiler: during the second visit to [[TheAlcatraz Hellena Prison]] to save King Albert]] and Haschel is required for the fight with [[spoiler: Gherich]] and every party member gets a special personal fight in the VeryDefinitelyFinalDungeon whether you leveled them up or not.
* Played straight for most of the game yet also subverted at one point in ''VideoGame/SailorMoonAnotherStory''. There are times in the game where you play as one set specific character or a set group of characters, and this holds for the first 3/5ths of the game. In the fourth "chapter" you're allowed to choose groups of Senshi, though Sailor Moon is usually required (in a few cases, Chibi Moon is). At the beginning of the fifth chapter, the Senshi split up, one group going to rescue Sailor Moon's little brother and the other to go visit the Crystal Palace. In the cut scene before choosing teams, it looks like Mars, Venus, Jupiter and Mercury are going with Sailor Moon, while the other five (the "Outers" and Chibi Moon) are the other group. However, aside from Chibi Moon and Sailor Moon, you actually can mix this up and choose whoever you want to be in which group. There is different dialogue in the cut scenes depending on who's in which group.
* In ''VideoGame/ShadowHearts Covenant'' and ''From The New World'', you don't ''need'' Anastasia or Johnny in every battle... but if you don't, you can't get the enemy's photos, because they're the ones with the cameras.
* The Required Party Members in ''VideoGame/{{Persona}}'' vary depending on which path you take. In the SEBEC Quest, your party will ultimately consist of the MC, Maki, Mark and Nanjo, with one slot left for you to choose, and in the Snow Queen Quest, your party consists of the MC, Yukino and Ayase, with two slots to choose.
* Nei in ''VideoGame/PhantasyStarII'' insists on coming with Rolf everywhere he goes [[spoiler:until she's murdered by her "sister" Neifirst]]. In ''VideoGame/PhantasyStarIV'', the party right up until the final dungeon is determined by the plot at any given point.
* ''VideoGame/DevilSurvivor'' occasionally has missions where you're required to dispatch a specific party member.
* ''VideoGame/EnchantedArms'' requires the player to always have the main character, Atsuma, at the head of the active party. Jarring, in that the game provides you with a large pool of optional "battle golems" to fill out the rest of your party. Not to mention that, in areas with enemies that either resist fire or possess strong water attacks, Atsuma can be a liability.
* ''NeverwinterNights2'' had an interesting take on this that alleviated the more annoying aspects of the trope. It forced you to take Shandra along for an entire chapter.... but raised the party member limit by one to accommodate her, allowing you to take whatever team you were comfortable with in the previous chapters, plus her. When [[spoiler: she died, the extra spot became open]].
* Some battles in ''FossilFighters'' require the player to use specific vivosaurs in their team.
* Every single character in ''AlterAila Genesis'' will be a Required Party Member at some point in the game. Many times in fact, as the plot continually divides and regroups the party. Thankfully near the end you can choose who you want in your party and who all you want to toss out out their butts.
* ''GuildWars'' features a few quests and missions which require a particular hero in the party. It also has the inverse; a quest in which you ''can't'' bring a particular hero, lest the correct [=NPCs=] fail to spawn.
* ''VideoGame/MassEffect2'' has Jacob, Miranda, Jack, and Garrus invariably join you before the second plot mission but the one with most impact on the plot is Prof. Mordin, whose genius provides most of the success-relevant tech on the ''Normandy''. However, you cannot expect to survive the SuicideMission without losses with just the required party members.
** You also have to bring each party member along on his/her loyalty mission, for what should be pretty obvious reasons. Because of this, loyalty missions tend to be tailored to the associated party member's special skills.
** ''VideoGame/MassEffect3'': Liara for the Thessia and (DLC) Eden Prime missions, Tali (if she survived 2) for the first and last missions of the geth-quarian arc, and [[spoiler: EDI]] for [[spoiler: the assault on Cerberus headquarters.]]
** The early missions in the third game force you to take along an exact party: Anderson on Earth, Ashley/Kaidan and James on Mars (until you meet Liara, then Ashley/Kaidan and Liara), and James/Liara on Menae (unless Garrus survived; then he'll replace Liara). In all cases, the game goes out of its way to justify what the other characters are doing, and you don't have anyone else in your party to bring.
** And throughout the entire game you have to pick up James, EDI, and Liara and they cannot be killed outside of a BadEnding or otherwise removed from the ship, nor is there any point in the previous games where they can die. Garrus is similar, but he can die in the finale of the second game, in which case he won't appear in the third.
* Franchise/{{Pokemon}} does this to some extent. It requires you to bring along a mon with certain special attacks if you want to get through certain dungeons. Particularly, you need Rock Climb to [[spoiler:face Red]] in [[VideoGame/PokemonGoldAndSilver HeartGold/SoulSilver]].
** Also sometimes a factor with event legendary Pokemon. You have to bring the three Legendary Golems, Regice, Regirock and Registeel, to Snowpoint Temple to wake up Regigigas in ''VideoGame/PokemonDiamondAndPearl'' and Platinum. (And unless you trade or use Pal Park to bring those mons over from ''VideoGame/PokemonRubyAndSapphire'', you need the special movie Regigigas to awaken the three golems in DPP, in order to wake up the other Regigigas.) Other examples include needing Celebi in your party to get Zorua and needing the three Legendary Beasts for Zoroark in ''VideoGame/PokemonBlackAndWhite''. In [[VideoGame/PokemonGoldAndSilver HeartGold/SoulSilver]], bringing the Pikachu-colored (Shiny) Pichu to Ilex Forest shrine is necessary to get Spiky-Eared Pichu.
** Other times, the event mons are needed to trigger in-game events. Black and White have specific events for Keldeo, Meloetta and Genesect, and ''[[VideoGame/PokemonRedAndBlue Pokémon Yellow]]'' has a surfing game that needs the Surfing Pikachu to activate. The Gold and Silver remakes have the Arceus Event, requiring an Arceus as your lead Pokemon to activate it, and the Giovanni battle, which requires specifically a DS-generation event Celebi to activate it.
* A staple in ''Franchise/DragonAge'':
** In ''VideoGame/DragonAgeOrigins'', you must bring Oghren on the [[spoiler:Anvil of the Void]] quest, Alistair to [[spoiler:the Landsmeet]], Zevran to the final fight against [[spoiler:the Crows, provided he chooses to stay with you]], etc. The various personal quests also require the companion they are associated with for obvious reasons except for Morrigan, who inverts it: her assignment requires you to ''avoid'' bringing her along when [[spoiler:you face Flemeth]]. On larger scale, you can kill or drive away pretty much any party member in the game except Alistair and Morrigan until the engdame (when you can drive even them away by [[spoiler:recruiting Loghain and refusing the Dark Ritual]], respectively). Ultimately subverted with Alistair during the FinalBattle, however: even though as a fellow Gray Warden, he is supposed to face the Archdemon with you, you can just as well leave him behind.
** In ''VideoGame/DragonAgeII'', most of the Companions' Personal Quests will require you to include them in the party. The one exception is Aveline's Act II Personal Quest [[spoiler:which involves her attempts to woo Guardsman Donnic (keyword: attempts)]]. There are also various points in the main plot in which companions may be required, such as Varric on the Deep Roads expedition.
* There are two points during ''VideoGame/MightAndMagic VIII'' where a specific character is required (above the undroppable hero). First the troll Overdune Snapfinger has to be recruited as a witness to the Lake of Fire's creation (this is not so bad, since it is still relatively early in the game, and the structure of the quest means no major combat is necessary during the parts where Overdune is required). Secondly, the cleric Dyson Leland is necessary for either variant of the quest where you align with the Clerics or the Necromancers (this ''is'' annoying, since Leland is liable to be more underlevelled than Overdune, and you have to take extreme measures to avoid having to have him in the party during the combat segments).
* This happens extremely often in ''VideoGame/TalesOfXillia2'', forcing an entire party formation on you for every story chapter but the last one, and requiring one or two specific members for the character episodes. Naturally, they end up making you have to fight ThatOneBoss using a formation that doesn't have any of the party's primary healers...
* All the party members introduced in ''VideoGame/EternalEden'' is integral to the plot in some way, and to make sure their role gets properly established throughout the game, one member always dies/leaves the party before a new one is introduced.

[[/folder]]

[[folder: Turn Based Strategy ]]

* ''FireEmblem'' has several chapters in most of it's games where a character is forced into the party and absolutely must be used for that chapter.
** Unfortunately, you usually have to keep them alive too, ie., you can't just let them get beaten and leave the field; if they get beaten, they're dead.
* In ''VideoGame/FinalFantasyTactics'', an {{NPC}} will occasionally take up one of your precious party member slots, most annoyingly in the [[LuckBasedMission Riovanes rooftop battle]] where Malak is [[spoiler: dead and can't be revived until the post-battle cutscene]] and a suicidally angry Rafa, who will charge headfirst into death unless your party is fast enough to intercept.
** In ''VideoGame/FinalFantasyTacticsA2'', you were often forced to take certain clan members on certain missions, mostly [[spoiler: Adelle's Heritor missions]] and sub-plots involving the [[OptionalPartyMember optional unique clan members.]]
* There are various points in ''VideoGame/CrossEdge'' where you'll be forced into using one or two other characters during a battle. York (Main character) and Raze get this treatment the most.
* ''VideoGame/SuperRobotWars'' games will automatically deploy certain units from time to time for plot reasons. In addition, recruiting optional characters or secret mechs often require specific characters to set flags.
* ''VideoGame/XCOMEnemyUnknown''s final mission requires you to have your brand new super soldier, the psyonic volunteer, on the team, if the volunteer dies, its game over. Interestingly, this soldier could be anyone up to the point that they are chosen, after this, they are TheHero.

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